These molecules exert multiple direct and indirect anti-myeloma effects, primarily through binding to cereblon (CRBN), part of an E3 ubiquitin ligase complex, and promoting the ubiquitination of the IKAROS and AIOLOS family transcription factors (IKZF1 and IKZF3) [2,3]. The gene discussed is IKZF1; the disease is plasma cell myeloma.